Snapping shrimp sound production patterns on Caribbean coral reefs: relationships with celestial cycles and environmental variables
The rich acoustic environment of coral reefs, including the sounds of a variety of fish and invertebrates, is a reflection of the structural complexity and biological diversity of these habitats. Emerging interest in applying passive acoustic monitoring and soundscape analysis to measure coral reef habitat characteristics and track ecological patterns is hindered by a poor understanding of the most common and abundant sound producers on reefs—the snapping shrimp. Here, we sought to address several basic biophysical drivers of reef sound by investigating acoustic activity patterns of snapping shrimp populations on two adjacent coral reefs using a detailed snap detection analysis routine to a high-resolution 2.5-month acoustic dataset from the US Virgin Islands. The reefs exhibited strong diel and lunar periodicity in snap rates and clear spatial differences in snapping levels. Snap rates peaked at dawn and dusk and were higher overall during daytime versus nighttime, a seldom-reported pattern in earlier descriptions of diel snapping shrimp acoustic activity. Small differences between the sites in snap rate rhythms were detected and illustrate how analyses of specific soundscape elements might reveal subtle between-reef variation. Snap rates were highly correlated with environmental variables, including water temperature and light, and were found to be sensitive to changes in oceanographic forcing. This study further establishes snapping shrimp as key players in the coral reef chorus and provides evidence that their acoustic output reflects a combination of environmental conditions, celestial influences, and spatial habitat variation. Effective application of passive acoustic monitoring in coral reef habitats using snap rates or snapping-influenced acoustic metrics will require a mechanistic understanding of the underlying spatial and temporal variation in snapping shrimp sound production across multiple scales.
KeywordsSoundscape Acoustic ecology Alpheidae Noise Passive acoustic monitoring US Virgin Islands
We thank Maxwell Kaplan and his field team Tom DeCarlo, Li Ling Hamady, and Samantha Zacarias for their efforts to collect the 2013 passive acoustic datasets. Thomas Kelley and the National Park Service provided assistance with permits. Financial support was provided in part by NSF Biological Oceanography Grant #1536782, as well as Woods Hole Oceanographic Institution’s Interdisciplinary Award and Postdoctoral Scholar Programs.
- Liu L, Berger VW (2014) Randomized Block Design: Nonparametric Analyses. Encyclopedia of Statistics in Behavioral Science. John Wiley & Sons Inc, Hoboken, NJ, USAGoogle Scholar
- Lobel PS, Kaatz IM, Rice AN (2010) Acoustical behavior of coral reef fishes. In: Cole KS (ed) Reproduction and sexuality in marine fishes: evolutionary patterns and innovations. University of California Press, Berkeley, pp 307–386Google Scholar
- Nolan BA, Salmon M (1970) The behavior and ecology of snapping shrimp (Crustacea: Alpheus heterochaelis and Alpheus normanni). Forma et Functio 2:289–335Google Scholar
- Shumway RH, Stoffer DS (2006) Time Series Analysis and Its Applications: With R Examples. Springer Science & Business Media, New York, NY, USAGoogle Scholar